Heating method and apparatus



Junel,1926,

'F. X. GOVERS HEATING METHOD AND APPARATUS Filed April 2. 1921 F. X.-GOVER$ y 'HEATING METHOD AND vAPPARATUS I i Filed April-2, 1921 ssheets-sneeta MQW `June l' 1926.

F.A GOVERS HEATING METHOD AND APPARATUS Fled4 April 2. 19,21

5 Sheets-Sheet 5l Patented Junei, 192e.v y

PATENTtoFI-flca;

FRANCIS X. GOVERS, OF NEW- YORK, N. Y.

HEATING METHOD AND APPARATUS.

Application med Aprile, 1921. 'serial No. 458,030.

This invention comprises a novel process and apparatus applicable to theheattreatment at relatively high temperatures of a wide variety ofsubstances, but more particularly such substances as exist, at thetemperature in question, in a fluid state, and require for their properand economical treatment a high rate of heat transfer between the fluidmass and the heating or heat- 'controlling medium. Such conditions arisein many commercial operations, particularly such as involve some changeof physical or chemical state in the charge under treatment, typicalexamples being the distillation, either with or wit-hout cracking orlother` decomposition, of mineral bils and other hydrocarbons; thecondensation of vapors at high temperatures; and chemicalreactions ingeneral, whether exothermic or endothermic, where the heat developmentor absorption occurs or is liable to occur at a high rate, and the heatmust in consequence be transferredat a high rate from or to the chargein order effectively to n control its temperature. .Y

Accordingvto my invention I circulate a liquid heat-controlling mediumin thermal contact, but out of physical contact, with the material to betreated, the heat-controlling medium being one which is solid at normalor higher temperatures (say C. or higher) but exists at the desiredoperatin temperature as a mobile but chemically an physically stableliquid. Examples of media of this type are lead and fusible lead alloys,such as lead-tin alloys of the solder type; but my invention isnotlimited to these materials, or even to materials of metallic nature,since for certain nrposes I may employ other fused or mo ten bodies ofhigh stability-and mobility, as forV example fusible salts 'orsalt-mixtures of which many are known, in connection, for exam le, withthe highly developed art of electro yzing fused baths for the productionof sodium, magnesium, aluminum and other metals.

Material such as lead, solder, etc., are, however, particularlyadvantageous because of their high specific heat per unit of volume duetol their great density, and also because of their capacity for rapidlyabsorbing, de livering and transferring heat. Moreover, heating media ofthis type may be used indefinitely without exhaustion or replacement; y

My invention is particularly applicable to hightemperature reactionsofthe kind described and for this purpose the heat controlling mediumshould lbe one which is liquid and stable at temperatures upwards of 400C.

It is well understood that many, if not most, chemical reactionsrequire, for the best results, to be carried out within a definitetemperature range which is often re# stricted to a very few degrees ofthe thermometric scale, a more or less deiinite pressure being alsooften requisite; but even where the optimum reactino conditions aredefinitely known, great difficulties arise in practice, on anyconsiderable operating scale, in continuously maintaining such optimumconditions; more particularly, as stated above, in those cases whereinheat is absorbed at a rapid rate (vaporization processes, endothermicreactions, etc.) or is liberated at'a rapid rate (condensation of vaors', exothermlc reactions, etc.). Such di culties are, of course,greatly accentuated in those cases, which are of common occurrence, inwhich the first reaction Istage proceeds with strong heatevolution,followed,

y a stage requiring the supply of heat. M present invention `1sapplicable to all suc 1. conditions, and is effectivefor the very closecontrol of temperatures even at relatively very high temperature ranges.

In a simple embodiment, myy invention contemplates circulating aheat-controlling medium, such as a fusible alloy of lead Vso and tin,through a closed system of high heat-conductivity (steel or ironv wallsor special metals or materials required by the particular conditionsorwhich may be desired for catalytic effects) this systembeing at onepoint in extended thermal, contact with the charge to bev treated, andat another point provided with heatJadjusting means (reheating furnaces,etc.) adequate to control the temperature of the medium brought int-othermal contact with the charge. The medium is positively circulated byappro-- priate devices, such as centrifugal pumps or the like, the rateof circulation being controlled according to the specificv r hirements.For example, in case a large odyof mineral oil is required to b emaintained within narrow temperature limits for a definite time, themolten alloy may be circulated y 'through the thermal contact system,comor internal tubes or coils, or both ofthese prising, for example, asurrounding jacket,

elements, at such rate that the fall of temperature during transit inthermal contact f with the charge is less than the prescribedtemperature limits; thereby ensuring that no ortion of the chargecontacting with the ieated surfaces is subjected to a temperature eitherabove or. below the requirements.

' Similarly incase of exothermic reactions, a

i this manner'of vcontrolling the temperature lends itself readily toeither small or large scale unit reduction, and to operations of eitherbatch) or continuous type.

Since the heat-controlling media contemplated herein are solid atordinary temperature ranges, means for bringing the wa ls of the'circulating system preliminarily to aV tem erature suliicient to ensureagainst obstruction through freezing orjsolidificatlon of the medium areprovided. This maybe accomplished in various ways, including electricalresistance heating, etc.; but I p revfer to employ super-heated steam ashereinafter fully disclosed. i

The resent invention is to be clearly dist' isliedv from processeswherein molten I' lea or the like is showered down through a li uid bathor otherwise brought into physiciil Such `processes do not lendthemselves .to conditions requir-l ing close temperature control, arewholly'inthe heat absorbing chamber 6, absorbing contact with thecharge.

applicableto baths or charges capable of reacting with lead orequivalent heatlng media athigh tem ratures, and in general posses's\ fonly limite utility.

My invention. will be'ex lained by reference to certain specific emodiments thereof, illustrated in the accompanyingdrawwherein:

in 'lrepresents one form of appa- 'Iii' ratus,'jand-Figs.'II and IIImodifi forms.

' 'Befe'rrin' V. to Fig. yLa furnace 1 is shown and a vesse 2 is'`rprovided into which the material .to 'be 4heated `i`s introducedby theinlet valve 3 and frorri'whichitmgy befwithdrawn bythe outlet valve-4. e1

je temperaturecontrolling medium cir-1 l j typ'e illustrated in 1g'. 1,having a' 'grate' 25 clstirr'gsystm' Icomprises the auular yheat system.

g heating system comprises the annular cham er 12 surrounding the heattransferring chamber 5 of the vessel 2, and the heating coil 13 in thefurnace 1 (which may be placed within the heat absorbing chamber 6 asillustrated), Iand the communieating pipes and jackets 14, 15, 16,17,18,

which, as indicated, substantially enclose or ,y

are enclosed'by the temperature controlmedium circulating system, sothat in starting the apparatus heat may be transferred by thepreliminary heating system vto substan- "tially all parts of the mediumcirculating system, so as to fuse the medium and make circulation of themedium possible.

.In the preliminary heating system superheated steam may be convenientlyused, being forced into the system through the inlet pipe 19 of the coil13, further heated inl its passage downward through.i that coil, andthen transferring its heat to and fusing the medium as it passes"through pipes 14, 15, 16, the chamber 12 and the jackets 17 and 18. Avalve 20 is conveniently located in the pipe 14 toishut olf the flow. Inthe chamber-12 adraw-off valve 21 is provided to remove any condensationthat may be formed and to regulate the pressure in the system and therate of flow through the chamber 12.

When the temperature controlling medium has been fused, the pump 11 isstarted, causing the same to begin circulation. The supply of steam forthe preliminary heating fs tem may then be cut off, for obviously t iepreliminary heating system will not have to be used again unless anduntil the medium -lll) is allowed to solidify in part or all ofthe lfhe`medium passes downward through heat, and thence by the communicatingpipes 7 and `8 to thel heat transferringchamber 5. Thenit passes upwardthrough the chamber 5, leaving it -by the pipe'` 9 and passing throughthe pump 11 and pipe 10,y to the no y closingthe valve 20,the'preljminary to of thehe'at absorbing chamber again.

heatin jchamber12 may' `be exhaustedI throng the valve 22, if desired,for theip'ur-` i.

the heat 4 in the vessel ,2;

pose of conserving tie furnace 1 vandthefspeed regulating .Bf of thepump, 11 the 'rate andy conditions of* trolled.

from which'the vroductsiofcomi-iustion pass upwardly and ivide, somegoingrby itlie ilues 26, 27 and28 to the chimney 29, thus of the chainbei 6,`and it also absorbs heat and radiates the same upon theiiinerlwall's of the chamber 6. The modified apparatus shown in Fig. IIis essentially like that of Fig. I just described, butit has theadvantage-of provid` ing a larger heating surface within the heatingvessel. It is sometimesl desirable, in cases where catalytic action ofthe heatiner surface plays an important part. In suc case the heattransmitting coil is either made of or plated with catalytic material.

Referring to-Fig. II of\ the drawings; 101 is a furnace and 102` is a.veel into which the material to be treated may be introduced by theinlet valve 103 and withdrawn by the outlet valve 104. l

The medium circulating system comprises the heat transferring coil' 105(which v'is hung i in the rack 105a in the vessel 102)', the heatabsorbing coil 106 (which is hung in the rack 106" in the furnace `101),land thecom` municating pipes 107 and 108 (below), and

109 and 110 (above), and the pump 11,1.'

This medium circulatin s stem filled with lead, solder, or other suitale material as de-4 scribed in connection with Fig. I.

The preliminary heating 'Sstem comprises the interior coil 112 inside tthe interior coil 113 inside the coil 106, and the communicating pipesvand 'jackets 114, 115, 116, 117, 117" and the jacket 11 8.` Superheatedsteamv is forced into this preiminary heating system by the (pipe 119,heated furtherin passing downwar through the coil 113; thence itapassesby pipes 114, 115 and 116 to the coil 112,- and downwardly throu h thatcoil, escaping by the ipe 117 into t e jacket 118 and bein final y drawnofi' through the pipe 121. T e flow may be controlled by the valves120'in the pipe 114.i4

and 122 in the outlet pipe 121.

n will be clear from Fig. ii that the pref.'

liminary heating s stem surrounds or is surrounded by su stantially the`entire.

medium circulatingsystem and thus readily permits the transfer of vheatto melt the circulating medium in starting operations.

The operation and control of the device of Fig. II is like that of thedevice of Fig. I.

The furnace shown in Fig. II comprisesl the grate 125, andlues 130, 131and 13 2 and bai 133.. Since the coil 106 is permeable e coil 105', and'bythe products of combustion, the separate lues provided in Fig. I forheating the exterior and interior walls of the chamber 6 are not neededwith the form of apparatus yillustrated in Fig. II.

In the modification shown in Fig. III, 1 represents the furnace shown inFigure I. Since the construction vand roperation of all parts of theapparatus within this furnace may be the same-as that heretofore illus-`trated and described in connection with the apparatus of Fig. I, theyare not again described.

. The steam pipes and jackets of the preliminary heating system 14, 15,16, 17 and 18 and valve 20 are also as shown and described in Fig` I,but the pipes 17 and 18, instead of communicatingy with an annular steamchamber 12 asin Fi I connect with thelarge 4casing 212 whic surroundsthe temperature controlling medium coil 205." The ow 'of steam for.preliminary heating is controlled by the valve 221.

Again the pipes 8, `9 and 10 and pump 11,

'which' deliverl and` withdraw the. temperature controlling mediuml asdescribed inconiiection with Fig. I insteadofcommunicat- 'ingwith theannular heat transferrin chamber 5 as in Fig. I, .connect with t e heattransferrin coil 205. Withi-nthe heat transferring coi 1205 isv the coil202 into which the .material to be treated is forced by the pipe 203 andfrom which it is withdrawn by the pipe 204. Thus the material to betreated is forcedthrough the coil 202 in countercurrent to thetemperature controlling medium :in the coil 205. By this arrangement avery fine adjustment of temperature ma be obtained. v

Iyrom the foregoing description it will be obvious that many changes maybe made inthe form and detailsA of the apparatus and process withoutdeparting :fromv the spirit and scope of my invention.

What I claim is:

1. Process for thermally treating. a charge under.temperature-controlledA conditions,

conditions llO iis

charge, said inedii'imV being so id at normal charge, Areheating a'closed circulating sys-` tem in t ermal contact with the char e), andthen mechanically circulatin theretrough in thermal contact but out o`physicalfcom tact with thev charge, a temperature-controlmediun'ivlconsists of molten."

-tem erature but liqi'iid and sta 4,le latjthe opto lclaim `1 which leotemperature-controllin ling medium which is Huid and stable attemperatures upwards of 400O C.

5. Process according to claim 4 in which the circulating medium consistsof molten metal or alloy. v

6. Process according to claim 4 in which ythe circulating mediumcomprises molten closed mechanically circulating system in thermalcontact but out of physical contact with the charge in said container,and a temperature controlling medium solid at normal temperatures butfluid at operating temperatures.

8. Apparatus for thermally treating nia'- terials undertemperature-controlled conditions comprising in combination, acontainer, means for mechanically circulating in a Howiiig stream atemperature-controlling medium through a closed circulating systeminthermal contact but out -of physical contact with the charge in saidcontainer, and means independent of the circulating medium for heatingthe circulatory system.

9. Apparatus for thermally treating materials undertemperature-controlled conditions comprising in combination, acontainer, means for mechanically circulating in a flowing stream atemperature-controlling medium through a cl'f'sed circulatin s' steminthermal contact btfout' of physica contact with the charge in saidcontainer, meansexterior to saidv container'for supplying heat to thecirculating medium, and means indeto the circulating medium, and atemperature controlling medium fluid and stable as Huid at temperaturesupwards of 400, C.

11. Apparatus for thermally treating materials under temperature controlconditions comprising in'combination a container, means for mechanicallycirculating a temperature controlling medium through a closedcirculating system in thermal contact out of physical contact lWith thecharge in said container, means exterior to said con` tainer forsupplying heat to the circulating medium, additional means for heatingthe circulating system andV a tem erature con? trolling medium fluid andstab e at temperatures upwards of 400'C.

FRANCIS GOVERS.

